One year ago — on Aug. 5, 2015 — an EPA crew at the Gold King Mine in southwest Colorado accidentally unleashed 3 million gallons of orange water filled with mercury and arsenic.

The toxic spill flowed into the Animas River, eventually running into New Mexico's San Juan River and into Lake Powell. So far, disaster response and water quality monitoring have cost the EPA about $29 million — and the problem isn't over yet.

Mesa Verde National Park in southwest Colorado is known for its iconic cliff dwellings, but archaeological artifacts left by the Ancestral Pueblo are all over. Rocky remnants of homes and farming sites are scattered throughout the dense pinyon juniper forest.

The rates will go up despite the fact that visitation at parks is up, which means bigger crowds, congested traffic and busier visitor centers. But more people aren't translating into a big boost for park budgets. For example, visitation at Rocky Mountain National Park in Colorado is up 20 percent so far this year and Yosemite, Yellowstone and Zion are also seeing double-digit increases. The parks are also seeing the strain. About 100 parks are planning an entrance fee hike.